Colorized Bacteria

This is an SEM image of bacteria infested mouse intestine. It took me several evenings to colorize it with Photoshop. Those tiny bacteria took forever to loop. The sample was provided by Ivalyo Ivanov of the Littman lab in the NYUMC Skirball Insitute. Click to enlarge.
I worked on this sample on a Zeiss Environmental SEM called the EVO but couldn't get very good results. So, we decided to work directly with Zeiss to get improve them. My boss traveled to Harvard and worked with Doug Wei from Zeiss on another Zeiss microscope called the VP Supra SEM. The difference between the EVO and the Supra is that the EVO can image wet samples but has a tungsten filament. The combination produces lower resolution images. The Supra can do variable pressure EM so there is a little more sample prep involved, but you don't have to coat the sample with metal, and this microscope also uses a Field Emission Gun that produces images with much better resolution. We've applied for a grant to purchase this instrument. If it's approved we can get one for our lab and do similar work.
To the right is the original image. It was taken on the Zeiss VP Supra by Doug Wei and colorized by me in Photoshop.

Microscope Collection

So, last week I talked about an amazing collection of microscopes at the University of Arizona College of Optical Sciences. This week, I decided to share my collection of microscopes with you. Again, they are not so much antique as they are vintage. The smaller one (right)was likely a model for school children in the 1940's or 50's. It came in a neat wooden box containing a few tools, a slide, and an old catalog from the company. Here (left) is an image I took with it of a piece of mica that i found in some potting soil.

The larger one (bottom right) with the odd looking bar is an old Carl Zeiss model (#316645 if you're interested). I consulted with a director of the Zeiss historical society about what it is and what it's function was and he thinks that it was measuring tool designed by Zeiss for use in the Zeiss factory for a quality.

Both of these microscopes were rather affordable. Probably because they were both extremely dirty when I bought them. They were obviously well used, especially the Zeiss. I spent several pleasant evenings in harsh light with a long drawn out whiskey, carefully removing every screw, opening every objective and condenser, polishing every lens, and loving every minute of it before putting it all back together. By the end, they look more or less brand new. In the Zeiss, I found a protractor in the eye-piece that I carefully aligned into the CORRECT position (the factory apparently neglected to do so in manufacturing). I also found a small prism in there.
Click the images to enlarge them.

Helium Ion Microscope

This week, we hosted a visit from Zeiss. They gave a presentation on a new technology that they just acquired called a Helium Ion Microscope. I remember seeing this demonstrated two years ago at the Microscopy & Microanalysis Convention in Chicago. Allis, which was purchased by Zeiss two years ago was the company that successfully figured out how to make it work.

This is a devise similar to a Scanning Electron Microscope, but uses Helium ions to create secondary electrons off the sample instead of an electron beam. This has advantages of getting much better resolution (due to it's incredibly small virtual source of three atoms), and an amazing depth of field compared to standard SEM. I think that this tool has the potential to replace the Scanning Electron Microscope, but they're about twice as expensive as a high-end SEM right now. There are only 7 being used in the world right now (soon to be 8). One is at Harvard and there is another in Singapore (where the speaker is teaching right now).
In all, the event was a success. Thirty plus people showed up from all over the New York area including people from Rockefeller University, the New York Structural Biology Center, and the New York University School of Medicine.